Fetal razor: an aid for scalp sampling.

The clinician's goal in the management of fetal distress is to diagnose the problem accurately and to begin treatment before fetal hypoxia leads to permanent neurologic squelae. Fetal heart rate monitoring should be considered a screening technique. If the heart rate remains normal, the chance of significant fetal acidosis is minimal. If periodic changes (either late decelerations or severe variable decelerations) occur, the sampling of fetal scalp blood can help substantiate the presence of fetal asphyxia. HON and KHAZIN [1] have shown that the pH system has a rapid response to, and "short memory" for, occasional umbilical cord compressions. As this periodic change worsens, or as late decelerations develop, the insult is more profound and pH depression may last as long as an hour. Hence, the clinician should remember that a sample of scalp blood assesses fetal status at one moment only; as labor progresses, additional biochemical evaluations may be necessary. Fetal scalp sampling was introduced by SALING [3]. Because of the wide disparity in the literature of normal values for the pH of fetal scalp blood during labor (7.45 to 7.25), each institution should establish its own normal range. In order to reduce the possible adverse effects of supine hypotension, a block should be placed under the parturient so that she is in a 15° tilt to